High-resolution optical coherence tomography imaging in KCNV2 retinopathy

Area of Science:

• Ophthalmology
• Genetics
• Medical Imaging

Background:

• Cone dystrophy with supernormal rod electroretinogram is a rare, childhood-onset, recessive retinal dystrophy.
• Mutations in the KCNV2 gene are the underlying cause of this condition.
• Early diagnosis and understanding of disease progression are crucial for potential therapeutic interventions.

Purpose of the Study:

• To identify novel spectral domain optical coherence tomography (SD-OCT) findings in patients with KCNV2 retinopathy.
• To report new mutational data in patients diagnosed with this condition.
• To correlate imaging findings with genetic mutations and disease progression.

Main Methods:

• A comparative case series study involving 12 patients with suspected KCNV2 mutations.
• Clinical examination, electrophysiological testing, fundus photography, and autofluorescence imaging were performed.
• Spectral domain optical coherence tomography (SD-OCT) was used to evaluate retinal layer appearance and thickness, and KCNV2 gene sequencing was conducted.

Main Results:

• KCNV2 mutations were identified in all studied families, with five novel mutations discovered.
• SD-OCT revealed characteristic bilateral foveal morphological changes, including discontinuous inner and outer segment (IS/OS) junction reflectivity, loss of the IS/OS line, and reduced foveal depth.
• Thinning of the neurosensory retina was a consistent finding across all affected eyes.

Conclusions:

• Foveal morphological changes are detectable using SD-OCT in the early stages of KCNV2 retinopathy.
• A critical window exists for therapeutic intervention, such as gene replacement therapy, before significant structural damage occurs.
• Early detection of these SD-OCT findings may guide timely treatment to potentially rescue retinal function.